Frequency converter



FIG. 1 is a perspective view of a frequency converter showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a second perspective view thereof; and

FIG. 9 is a third perspective view thereof;

FIG. 10 is a perspective view of a frequency converter of a second embodiment showing our new design;

FIG. 11 is a front view thereof;

FIG. 12 is a rear view thereof;

FIG. 13 is a right side view thereof;

FIG. 14 is a left side view thereof;

FIG. 15 is a top view thereof;

FIG. 16 is a bottom view thereof;

FIG. 17 is a second perspective view thereof;

FIG. 18 is a third perspective view thereof; and,

FIG. 19 is a fourth perspective view thereof.

The broken line showing of the frequency converter represents unclaimed subject matter and forms no part of the claimed design. 

CLAIM The ornamental design for a frequency converter, as shown and described. 